Brown, Delmer and Ichiro Ishida, eds. (1979). [ Jien, c. 1220], Gukanshō; "The Future and the Past: a translation and study of the 'Gukanshō', an interpretive history of Japan written in 1219" translated from the Japanese and edited by Delmer M. Brown & Ichirō Ishida. Berkeley: University of California Press. ISBN0-520-03460-0